Furnace.



PATENTED JAN. 3, 1905.

C. MOMILLAN.

FURNACE.

APPLICATION FILED JULY 11, 1903.

ZZZ/7s wS es 1315 UNITED STATES Patented January 3, 1905.

PATENT OFFICE.

FURNACE.

SPECIFICATION forming part of Letters Patent No. 779,371, dated January 3, 1905.

Application filed Ju1yl1,1903. Serial No. 165,064.

To all whom it may concern.-

Be it known that I, CHARLES MCMILLAN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Furnaces, of which the following is a full, clear, and exact specification.

My invention relates more particularly to that type of steam-boiler furnaces in which the boiler-sheets are provided with fire-brick or other fireproof material for the purposes, primarily, of constituting an incandescent surface for burning the smoke and other volatile products of the fuel; and my invention has for its primary object to provide an incandescent surface of the maximum area and at the same time leave a material percentage of the boiler-sheet exposed to the direct action of the heat.

A further object of my invention is to provide improved means for holding the fragments of the fire-brick or other fireproof material should the same break or crack, and thus prevent their dislodgement from the boiler; and a still further object of my invention is to provide simple and convenient means for supporting the brick or other sections of fireproof material against the boiler in such a manner that a brick may be renewed at any point on the boiler-surface without removing the others.

With these ends in view my invention consists in certain features of novelty in the construction, combination, and arrangement of parts by which the said objects and certain other objects hereinafter appearing are attained, all as fully described with reference to the accompanying drawings and more particularly pointed out in the claims.

In the'said drawings, Figure 1 is a perspective view of a part of the boiler-shell, partially in section and partially broken away, showing my improvements applied thereto. Fig. 2 is an enlarged detail perspective view of three of the sections which constitute the brick-supporting bars, showing the same in their relative arrangement before being placed together. Fig. 3 is a longitudinal sectional view of one of such bars, showing it in position on the boiler with the bricks supported thereon. Fig. 4 is a transverse sectional view on the line 4 4, Fig. 5, of one of such bars and the bricks supported thereon, illustrating a modification hereinafter explained; and Fig.

5 is a longitudinal sectional View thereof,

taken on the line 5 5, Fig. 4.

1 is the boiler-shell, the bottom and sides of which at points where exposed to the heat of a furnace are provided with a series of longitudinal parallel rows of fire-brick 2 or brick composed of any other suitable fireproof material capable of becoming incandescent and maintaining the heat in a degree requisite for burning the smoke and other volatile products of the fuel. These rows of fire-brick are arranged a considerable distance apart, as shown in Fig. 1, so as to expose the boiler to the direct action of the heat between the rows of brick, and thus providing for quick steaming, while the rows of fire-brick serve to hold the heat and burn the volatile products of the fuel after combustion is well under way. These rows of fire-brick, it will be seen, are also semicylindrical in cross-section, so as to at onceaiford room for the brick-supporting bars, which I will presently describe, and provide a maximum area of incandescent surface without formation of abrupt corners or edges liable to break or chip off.

The bricks 2 are supported on the boiler by longitudinal bars secured to the bottom and sides of the boiler by any suitable means, but preferably by means of stud-bolts 3, which are screwed into the boiler-plates and the bars, respectively. These bars are formed with T- heads 4 and perpendicular shanks or webs 5, while the inner or upper sides of the bricks are formed with keyhole-slots 7, which permit of the bricks being slipped over the T- heads 4 longitudinally with the shank 5 of the bar in the narrow portion of the slot 7. These bars, however, are preferably composed of short interlocking sections, as shown in Fig. 2, all of which have the heads 4 and shanks 5; but only every alternate one of these sections is provided with one of the studs 3, the intermediate section having projecting lugs 8 at each end, constituting extensions of its shank 5 beyond the ends of its head 4, and these extensions or lugsS project over and rest upon the upper or inner sides of the heads 4 of the l adjacent sections, and in order that the detachable intermediate section may be held in alinement with the two fixed sections, espevided at each end with a rabbet 9, which receive the lugs 8 and are of the same depth or lateral dimension as the lugs, so that the shanks 5 of all the sections will be in line and flush with each other at the sides and top. The intermediate detachable section l'iaving the lugs 8 being as long as one or more of the bricks 2, it will be seen that the bricks may be renewed at any point in the line or row Without entirely removing all of the bricks outside of the one to be renewed, and when putting the bricks in place these detachable sections afford the combined method of introducing the bricks at Various points in the length of the row without necessarily inserting them all from the end of the row. In the rows which occur at the sides of the boiler it is obvious in many instances that both the flanges and the T-heads 4 are not necessary, and therefore, if desired. the bars on the sides may be provided with L-shaped heads 10, as shown on the right-hand side in Fig. 1, the supporting-bars otherwise being the same as shown in Figs. 2 and 3 and also composed of fixed and detachable sections, as already described. When these L-shaped heads 10 are employed, however, the bricks may be formed with L-shaped slots 11 instead of the keyholeslots; but the narrow portion 12 of these L- shaped slots are as wide as the heads 10 and shanks 5 combined, so that the heads may be inserted, or, more properly speaking, the brick inserted, over the head and then allowed to drop down into position, with a part of the brick engaged between the boiler and the inner side of the head and the lower side of the brick hanging against the boiler. This form of supporting-bar, however, is only suitable for the sides of the boiler without some means of holding the free side of the brick from sagging away from the boiler, and thus permitting the sulfurous fumes to reach and destroy the supporting-bars.

In order that the intermediate detachable section of the bar which carries the lugs 8 may be held snugly against the surface of the boiler and in perfect alinement at its under side with the other two sections, it is desirable to have the lugs or extensions 8 a little small for the space between the boiler and the upper surface of the heads 4, so as to insure their introduction and to then make them tight by the insertion of one or more shims 13. of mica or other suitable fireproof heat-conducting material, between their under or outer sides and the heads 4, as shown in Fig. 3.

In Figs. 4 and 5 I have shown a device for holding the fragments of the brick on the supporting-bar at either the bottom or the sides of the boiler in the event the brick should crack or break. This consists of a strap 14, of metal or any other suitable material, having downturned lugs 15 at each end, which is inserted between the boiler and any one or all of the sections of the brick-supporting bars, with the lugs 15 turned outwardly or downwardly and embracing the sides of the brick, the shank 5 of the bar-section being cut away transversely, as shown at 16, for the passage of the strap 14, and the sides of the brick, if desired, being recessed, as shown at 17, for receiving the lugs 15, which are afterward covered or concealed by a quantity of fire-clay 18 or any other suitable fireproof material. This holding device 14 15 may of course be employed with either form of bricksupporting bars.

Having thus described my invention, what I claim as new therein, and desire to secure by Letters Patent, is

1. In a steam-boiler furnace the combination of a boiler-shell and fireproof material thereon in a plurality of longitudinal rows with spaces between them exposing the boiler to the direct action of the heat.

2. In a steam-boiler furnace the combination of a boiler, bars for supporting bricks on the boiler composed of sections, means for rigidly securing each alternate one of said sections to the boiler, each of said sections having a head formed at its outer side longitudinally thereon and a narrow shank extending from said head to the boiler and some of said sections being detached from the boiler and removable and having end extensions lapping over and supported upon said fixed sections, and fire-bricks having slots complementary in shape to said shanks and heads and inserted thereover against the boiler.

3. In a steam-boiler furnace the combination of a boiler, a bar for supporting the bricks on said boiler composed of sections each having a head formed longitudinally thereon at its outer side, and a narrow shank extending from said head to the boiler, some of said sections being rigidly secured to the boiler and sections between said secured sections being detached from the boiler, said secured sections having the sides of their shanks rabbeted above said heads and said unsecured sections having extensions overlapping said heads and fitting in said rabbets, and firebricks having slots complementary in shape to said shanks and heads and inserted thereover against the boiler.

4. In a steam-boiler furnace the combination of a boiler, L-shaped supporting-bars secured to the boiler and fire-bricks having L- shaped slots inserted over and suspended upon said bars.

5. In a steam-boiler furnace the combination of a boiler, a brick-supporting bar secured to the boiler and having a head and a shank extending from the head to the boiler,

a fire-brick supported by said head against the boiler and a retaining-strap inserted between the boiler and the brick and having means engaging the side of the brick for holding the brick on said bar in the event the brick should crack.

6. In a steam-boiler furnace the combination of a boiler, a brick-supporting bar secured thereto, a brick supported on said bar, a retaining-strap let into the upper or inner edge of the bar between the bar and the boiler and having its end flanged against the brick for holding the brick on the bar in the event the brick should crack.

7. In a steam-boiler furnace, the combination with a boiler-shell and fire-box, of a mul- CHARLES MCMILLAN.

Witnesses:

F. A. HOPKINS,

M. B. ALLSTADT. 

